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- /*
- ** $Id: lapi.h $
- ** Auxiliary functions from Lua API
- ** See Copyright Notice in lua.h
- */
- #ifndef lapi_h
- #define lapi_h
- #include "llimits.h"
- #include "lstate.h"
- /* Increments 'L->top', checking for stack overflows */
- #define api_incr_top(L) {L->top++; api_check(L, L->top <= L->ci->top, \
- "stack overflow");}
- /*
- ** If a call returns too many multiple returns, the callee may not have
- ** stack space to accommodate all results. In this case, this macro
- ** increases its stack space ('L->ci->top').
- */
- #define adjustresults(L,nres) \
- { if ((nres) <= LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
- /* Ensure the stack has at least 'n' elements */
- #define api_checknelems(L,n) api_check(L, (n) < (L->top - L->ci->func), \
- "not enough elements in the stack")
- /*
- ** To reduce the overhead of returning from C functions, the presence of
- ** to-be-closed variables in these functions is coded in the CallInfo's
- ** field 'nresults', in a way that functions with no to-be-closed variables
- ** with zero, one, or "all" wanted results have no overhead. Functions
- ** with other number of wanted results, as well as functions with
- ** variables to be closed, have an extra check.
- */
- #define hastocloseCfunc(n) ((n) < LUA_MULTRET)
- #define codeNresults(n) (-(n) - 3)
- #endif
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